go/zodb/*: Fix Python database generators to work with ZODB5 + preserve DB compatibility with ZODB3

Paralleling nexedi/zodbtools@0b6f99da.

All test databases in */testdata/ stay as before bit-to-bit the same.

go/zodb/btree/testdata/gen-testdata

 #!/usr/bin/env python2
 # -*- coding: utf-8 -*-
-# Copyright (C) 2018  Nexedi SA and Contributors.
-#                     Kirill Smelkov <kirr@nexedi.com>
+# Copyright (C) 2018-2020  Nexedi SA and Contributors.
+#                          Kirill Smelkov <kirr@nexedi.com>
 #
 # This program is free software: you can Use, Study, Modify and Redistribute
 # it under the terms of the GNU General Public License version 3, or (at your
@@ -23,6 +23,7 @@
 from ZODB.DB import DB
 from BTrees.LOBTree import LOBucket, LOBTree
 from ZODB.utils import u64
+from zodbtools.test.gen_testdata import run_with_zodb3py2_compat
 import os, os.path, transaction
 
 from golang.gcompat import qq
@@ -31,7 +32,7 @@ def rm_f(path):
     if os.path.exists(path):
         os.remove(path)
 
-def main():
+def main2():
     import zodbtools.test.gen_testdata  # to make time predictable (XXX)
 
     outfs = "testdata/1.fs"
@@ -87,6 +88,9 @@ def main():
     conn.close()
     db.close()
 
+def main():
+    run_with_zodb3py2_compat(main2)
+
 
 if __name__ == '__main__':
     main()

go/zodb/py/pydata-gen-testdata

 #!/usr/bin/env python2
 # -*- coding: utf-8 -*-
-# Copyright (C) 2017-2018  Nexedi SA and Contributors.
+# Copyright (C) 2017-2020  Nexedi SA and Contributors.
 #                          Kirill Smelkov <kirr@nexedi.com>
 #
 # This program is free software: you can Use, Study, Modify and Redistribute
@@ -20,11 +20,14 @@
 # See https://www.nexedi.com/licensing for rationale and options.
 """generate reference pickle objects encoding for tests"""
 
-from ZODB.tests import testSerialize
 from ZODB import serialize
+from zodbtools.test.gen_testdata import run_with_zodb3py2_compat
 from golang.gcompat import qq
 
-def main():
+def main2():
+    # import ZODB.tests at runtime after ZODB.X._protocol is patched
+    from ZODB.tests import testSerialize
+
     # dump to go what to expect
     with open("ztestdata_pydata_test.go", "w") as f:
         def emit(v):
@@ -52,5 +55,8 @@ def main():
         emit('\t{"aaa", "?.?"},') # invalid
         emit("}")
 
+def main():
+    run_with_zodb3py2_compat(main2)
+
 if __name__ == '__main__':
     main()

go/zodb/storage/fs1/py/gen-testdata

 #!/usr/bin/env python2
 # -*- coding: utf-8 -*-
-# Copyright (C) 2017-2019  Nexedi SA and Contributors.
+# Copyright (C) 2017-2020  Nexedi SA and Contributors.
 #                          Kirill Smelkov <kirr@nexedi.com>
 #
 # This program is free software: you can Use, Study, Modify and Redistribute
@@ -22,7 +22,8 @@
 
 from ZODB.FileStorage import FileStorage
 from ZODB import DB
-from zodbtools.test.gen_testdata import gen_testdb, precommit
+from ZODB.Connection import TransactionMetaData
+from zodbtools.test.gen_testdata import gen_testdb, precommit, run_with_zodb3py2_compat
 from os import stat, remove
 from shutil import copyfile
 from golang.gcompat import qq
@@ -142,17 +143,20 @@ def main():
     # prepare file with voted (not fully committed) tail
     voted = "testdata/1voted.fs"
     copyfile(outfs, voted)
-    vstor = FileStorage(voted)
-    vdb   = DB(vstor)
-    vconn = vdb.open()
-    vroot = vconn.root()
-    vroot._p_activate() # to know its current serial
-
-    txn = precommit(u"author", u"description", {'aaa': 'bbb'})
-    vstor.tpc_begin(txn)
-    vstor.store(vroot._p_oid, vroot._p_serial, '000 data 000', '', txn)
-    vstor.tpc_vote(txn)
-    # NO tpc_finish here so that status remain 'c' (voted) instead of ' ' (committed)
+    def _():
+        vstor = FileStorage(voted)
+        vdb   = DB(vstor)
+        vconn = vdb.open()
+        vroot = vconn.root()
+        vroot._p_activate() # to know its current serial
+
+        txn = precommit(u"author", u"description", {'aaa': 'bbb'})
+        txn_stormeta = TransactionMetaData(txn.user, txn.description, txn.extension)
+        vstor.tpc_begin(txn_stormeta)
+        vstor.store(vroot._p_oid, vroot._p_serial, '000 data 000', '', txn_stormeta)
+        vstor.tpc_vote(txn_stormeta)
+        # NO tpc_finish here so that status remain 'c' (voted) instead of ' ' (committed)
+    run_with_zodb3py2_compat(_)
 
     st = stat(outfs)
     l  = st.st_size